Among my missions in this life is the chore of explaining networking in general and the Internet in particular to policy makers and other citizens who don’t build network technology for a living. This is enjoyable because it combines so many of the things that make me feel good: gadgetry, technology, public policy, writing, talking, and education. It’s not easy, of course, because there are a lot of things to know and many ways to frame the issues. But it’s possible to simplify the subject matter in a way that doesn’t do too much violence to the truth.
As I see it, the Internet is different from the other networks that we’re accustomed to in a couple of important ways: for one, it allows a machine to connect simultaneously to a number of other machines. This is useful for web surfing, because it makes it possible to build a web page that draws information from other sources. So a blog can reference pictures, video streams, and even text from around the Internet and put it in one place where it can be updated in more-or-less real time. It enables aggregation, in other words. Another thing that’s unique about the Internet is that the underlying transport system can deliver information at very high speed for short periods of time. The connection between a machine and the Internet’s infrastructure is idle most of the time, but when it’s active it can get its information transferred very, very quickly. This is a big contrast to the telephone network, where information is constrained by call setup delays and a very narrow pipe.
Both of these features are side-effects of packet switching, the information transfer system used by the Internet and all the stuff that rides on it. Packet switching isn’t hard for people of reasonable intelligence to understand by reference to postcards and the like. Engineers can generally take such an audience on a productive trip through the essentials in a few minutes, even relatively unskilled ones. It’s not that hard.
Some of the people who make a living explaining the Internet to the mass audience get it all wrong, however. Most of these people are lawyers or law professors, which is kind of mystifying because they’re bright people and really should know better. One such example I encountered this week is an article in The New Republic by Tim Wu comparing the Internet to movies, radio, and TV. I’ve met Tim and find him to be a bright person, certainly brighter than many of this para-technical adversaries, so it’s odd that he would make statements that are simply ridiculous on their face. Wu invents a fictitious element:
History does not always repeat itself, to be sure; and it is possible that the Internet is different. Its most fundamental feature, after all, is a radical separation of distribution and content, which is the very opposite of the NBC/Paramount system…
The Internet’s wall between content and distribution also creates considerable power for those who can harness it. It is little appreciated how dependent the Internet’s business models are on a neutrality in the infrastructure.
How radical it would be, according to Wu, for someone to build a radio that could carry spoken words without regard for their language, message, political orientation, or emotional expression. Who could possibly imagine a movie theater capable of showing content produced by Warner, Sony, or Four Wall Productions? How revolutionary it would be if we had a transportation system capable of handling trucks laden with either the Wall St. Journal or the New York Times, instead of the tightly interconnected system we have today!
Where does this nonsense come from, and who can possibly believe it?
Wu is probably mislead by the language that engineers use when describing network structure (or “architecture” as we like to call it.) At the dawn of packet switching, we mistakenly guessed that each problem in the delivery of a packet could be solved once and for all at one point in the system and if we could identify these points we’d be on the right track to developing a general theory of network design and optimization. The embodiment of this idea was the Open Systems Interconnection reference model, which decomposed networks into seven functional layers from application (at the top) to physical signaling (at the bottom.) Somewhere in the middle a line was drawn between content and transport, or more pertinently between representations of content and systems of transport. But this structure was simply an abstraction that can be applied to any system of information or transport just as easily as to Internets.
Movies represent information as sounds and pictures on a strip of film, and films move from studio to theater in trucks. Replace the film with a disk file and substitute fiber optic cables for trucks and nothing changes in the realm of structure or description.
The Internet moves digital information, and it does so by copying bits and then discarding them. Bits move quickly and inexpensively because the ratio of information to mass in a digital system is very, very high. Walls of separation are fine and good in the realm of law, but they have very little to do with technology unless we want them to.
The Internet differs from old media technologies in terms of speed, cost, and reach, but not in structure. Now you know why.